If you arn't a completionist, I would probably pass on both. I am not a fan of Sideways in robot mode, and that red looks terrible. Much like Barricade, he has a great image in the CGI rendering, and although I know they can't make him like that, he just looks too goofy to me, and the red is aweful. Demolisher is just goofy. I don't mind him and think he is a pretty interesting concept, but I hope to make a stand for him soon so I can do something more with his limited posability. They both have decent vehicle molds IMO. But, if budget is a priority for you, I would wait till other figures are released, or save for one of the larger ones such as Leader Prime, or some of the HA versions if you don't have them yet.
Definitely Sideways. Unless you don't like the look of lanky insectoid robots. Basically look at a picture of the figure, if you don't like what you see, you still won't when you have it in hand. Also, some people are realy put off by the red plastic used on him. I got over it, but it is something to think about. I'd only recommend Demolishor if you absolutely must have a figure of this character. If you only have a passing interest in him, then he's an easy skip. On a side note, my Dem fig actually stands pretty well. I don't know if this is for all the figures, but the tread-wheels on mine are very stiff, so they don't really roll at all. You can rotate them, but you can't really push him along and get the wheel to actually turn. But because of this, he stands fine when put into a sort of tripod stance, with his arms slightly behind him.
Personally, if it was up to me, neither. Both of their bot-modes are horrible representations of their on-screen counterparts, imo. Though if you absolutely have to get one of them, get Sideways. He's half the price of Demolishor, and has the better alt-mode.
Definitely Sideways. It's deceptively awesome. Demolishor had a surprisingly involved and fiddly transformation, but the robot mode is still just a head with two wheels and arms growing out of it.
